NASA has joined ESA's mission to photograph two billion galaxies.

NASA is joining forces with the European Space Agency to launch a telescope into space with the goal of mapping and measuring around two billion galaxies, the administration announced Thursday. The information the telescope collects will help scientists map dark matter in the Universe and understand how dark energy has affected the Universe’s evolution over time.

The mission, named Euclid, is set to begin in 2020 and last for six years. NASA and the ESA will put the Euclid telescope into orbit at the Earth and Sun's Lagrange point L2. That's the area where the gravitational pull from both bodies balances enough so Euclid can remain stationary behind Earth, as seen from the Sun.

Throughout those six years, Euclid will map galaxies spread across approximately one-third of the sky. Based on the relative positions and ages of various galaxies, scientists can determine how the Universe has expanded since its beginning. The apparent acceleration relative to the state of the galaxies will allow them to more precisely understand the effects of dark matter and energy.

NASA will contribute 16 infrared detectors to the mission, as well as four more detectors for one of Euclid’s planned science instruments. NASA nominated three teams of scientists totaling 40 people to work for the Euclid Consortium; a group of 1,000 members led by the ESA are working on the mission.

Casey Johnston
Casey Johnston is the former Culture Editor at Ars Technica, and now does the occasional freelance story. She graduated from Columbia University with a degree in Applied Physics. Twitter@caseyjohnston

Perhaps "murky" would be more appropriate? I know there are bits of cosmological history where many kinds of light were obstructed, but I thought they included infrared as well, so I don't think "dark" is a reference to that.

It is the tradeoff of seeing many galaxies (billions) over a third of the sky, versus seeing a few very faint and distant galaxies.

Euclid is a survey telescope and sees lots of galaxies at merely large distances (say 7 billion light years). This is crucial for studying Dark Energy which only really starts to kick once the universe is 7B years old.

James Webb will see some of the first galaxies to form in the universe, about 13 billion light years away. James Webb needs to look much deeper into the infra-red and needs much larger mirrors to go after these faint galaxies. As with anything, there is a trade-off, and James Webb has focused on very large mirrors and deep infra-red optics, while Euclid concentrates on wide fields of view and correspondingly large sensors.

The analogy is not dissimilar from a wide angle camera lens (see lots of birds at once, fairly small lens) and a giant telephoto lens (can't see many birds at once, but can see one bird very well and has a huge lens). Being spacecraft, one doesn't use the same sensor on two lenses but launches the lenses as separate satellites (cheaper in the long run).

This is getting ridiculous. America needs to stop giving away know how, technology and parts of its space program to ESA or anyone else desperately try to get their hands and nose into America's space program.

Does this mean we'll be able to see the Big Bang? and if not, what would it take? could be hypothetically see the big bang if we went back in time a few million years? or would we have to travel across the universe and go back in time like 12 billion years to see it?

Does this mean we'll be able to see the Big Bang? and if not, what would it take? could be hypothetically see the big bang if we went back in time a few million years? or would we have to travel across the universe and go back in time like 12 billion years to see it?

This is getting ridiculous. America needs to stop giving away know how, technology and parts of its space program to ESA or anyone else desperately try to get their hands and nose into America's space program.

If the goal is science, cooperation saves money, time and even lives.

Ultimately the goal of all space exploration is about science. That doesn't mean America should be giving away what took so many decades and so much money to create and develop.

It's not really about giving away.You can walk 1 step per year alone or 3 steps per year with partners.

For example, I don't think America would ever fund the ISS alone. Without partnerships, there wouldn't be any ISS.

[QUOTE=Flashlight]This is getting ridiculous. America needs to stop giving away know how, technology and parts of its space program to ESA or anyone else desperately try to get their hands and nose into America's space program.[/QUOTE]

Apparently NASA is supplying 40 people and 20 detectors - ESA is supplying 1,000 people and the rest of the satellite / telescope / instruments. Seems like a fair deal, no?

Does this mean we'll be able to see the Big Bang? and if not, what would it take? could be hypothetically see the big bang if we went back in time a few million years? or would we have to travel across the universe and go back in time like 12 billion years to see it?

We cannot see the big bang. We are the big bang.

The universe was also transparent to light before the Recombination Epoch, as it was a plasma. You couldn't "see" anything.

It's a pun, since they will look at dark matter and dark energy of the past universe.

But going back means weaker images for us now, despite the sources being closer together, due to the triple whammy of light spread and volume increase (lower irradiance) and redshift (lower energy).

marcusj0015 wrote:

Does this mean we'll be able to see the Big Bang?

Depends on how you define big bang.

- Most people define it as the expanding universe we see and its cosmology. Since it is an expansion everywhere, we can see it in the increase of average redshift as we look further out. (Observing dark energy is part of that, looking at how the expansion accelerates as the universe gets older.)

- That is confusing though, since the new inflationary standard cosmology embeds the earlier mostly freewheeling expansion in a beginning inflation that sets it off and a finishing dark energy acceleration that dilutes it towards heat death.

I've seen cosmologists like Ethan Siegel define "Big Bang" as the first moment where you can observe a spacetime with particles and their well defined temperature and pressure. That temperature is some 3 orders of magnitude below the earlier Planck energy singularities of non-inflationary big bang cosmologies, so it makes the difference explicit. [ http://scienceblogs.com/startswithabang ... -big-bang/ ]

This is getting ridiculous. America needs to stop giving away know how, technology and parts of its space program to ESA or anyone else desperately try to get their hands and nose into America's space program.

This is getting ridiculous. America needs to stop giving away know how, technology and parts of its space program to ESA or anyone else desperately try to get their hands and nose into America's space program.

If the goal is science, cooperation saves money, time and even lives.

Ultimately the goal of all space exploration is about science. That doesn't mean America should be giving away what took so many decades and so much money to create and develop.

Last time I checked you couldn't even go to the ISS without Russian technology...not to mention the fact that big parts of the ISS come from all over the world...

This is getting ridiculous. America needs to stop giving away know how, technology and parts of its space program to ESA or anyone else desperately try to get their hands and nose into America's space program.

If humanity ever wants to get serious about space exploration, it's going to need to be a global effort. Nationalism and the other petty games we play against each other on this planet are only holding us back.

Disclaimer: I am an astrophysicist, but not one working on this mission.

International cooperation is definitely the right approach here. Let's look at the big picture: As mmorales noted above, Euclid will be complementary to JWST, able to survey a much wider area but in less detail and depth. With both telescopes operating at once, we'll be able to do a lot more than with either alone. Now, JWST (which I work on myself, among other things) is also an international collaboration, funded roughly 80% US, 15% Europe, 5% Canada. (No actual dollars or euros change hands between the nations, each contributes technology and personnel to different areas of the whole mission. For instance this past year Canada and Europe delivered one each of the four science cameras for JWST.) I can tell you from firsthand experience that this partnership is making JWST a better, stronger mission than it would be if the US tried to go it alone -- just as it has for Hubble, and for the ISS, and for Mars exploration. This isn't news. :-)

So what we're talking about here, is Europe taking the lead with the US as the minor partner on the wide-field survey mission Euclid, while the US takes the lead with Europe and Canada as minor partners on the small-field-but-superior-capabilities JWST. Seems fair to me.

At the same time, the US is also looking ahead to possibly leading its own wide-field mission at a later date. Remember last summer when it was announced that NASA was given parts for two unused spy satellites the size and quality of Hubble? The leading idea right now for what to do with those is to use one for an even more ambitious wide-field survey mission that would follow on after Euclid ("WFIRST"), to do additional galaxy surveys even deeper as well as other studies that require the wide field of view such as certain types of observations of exoplanets. It's still early on this - the community is getting organized, there are various study committees working out mission concepts and designing potential instrument suites, we're considering whether to also add in another instrument for direct imaging of exoplanets too, etc. There's time to work these details out, because the US won't have funding to start another new mission until after the funding on JWST starts to ramp down, at the earliest. That will happen starting around 2017, so we've got a few years to develop plans before a start late this decade and a launch maybe around 2025. Stay tuned!

Now, the other point that's worth noting is (and I'm going to try to say this without feeding any trolls) that nowhere in any of this are we really giving away our technologies. In return for becoming scientific partners in the Euclid mission and able to share in its data and discoveries, we're contributing something that we uniquely can make. The US is the world leader in infrared detectors, specifically the Hawaii-xRG family of devices made by Teledyne near Los Angeles. The technology of how to actually build these devices is very closely held, and is restricted against international dissemination by a set of laws called ITAR (that turn out to be a colossal pain for us all in terms of collaboration logistics, and which are finally in the process of being reformed a bit, but that's a side topic). The point is, the structure of these collaborations are set up such that each nation can contribute physical devices into the partnership, while each retaining their own intellectual property, trade secrets, etc. It's complex and can be bureaucratic at times - but this way of working together has a proven track record at achieving some of humanity's greatest scientific triumphs.

Plus it means I get to work at a research institute full of Europeans, which really improves the quality of the tea and coffee available here. :-)

If the artist's rendering is to be believed, they are putting solar panels on a satellite that will be stationed around Earth-Sun L2? That doesn't seem to make any sense. Am I missing something?

It's an official ESA rendering; so it should be reasonably correct. The Webb telescope is also being placed in an L2 orbit and will be solar powered. As a result my assumption is that the L2 orbit is wide enough that the Earth doesn't block the sun and that the distance is primarily to avoid earthbound sources of interference. The Webb's planned orbit is large enough to have unimpeded access to sunlight.

Disclaimer: I am an astrophysicist, but not one working on this mission.

One of the best things about ars technica is the incredible expertise lurking in the forums. I suspect mperrin is Dr. Marshall Perrin, "member of the Telescopes group at STScI, working on issues of wavefront control, optical modeling, and high contrast imaging in support of the James Webb Space Telescope." (In layman terms, one of the world experts on infra-red optics.)

If humanity ever wants to get serious about space exploration, it's going to need to be a global effort. Nationalism and the other petty games we play against each other on this planet are only holding us back.

Goes without saying...

Unless a major technological breakthrough occurs where launches get a LOT cheaper, most nations can't afford to go it alone at this time.

Sure, nationalism, prestige and an arms race had a lot to do with the space race culminating in Project Apollo--but those times are long gone.

Disclaimer: I am an astrophysicist, but not one working on this mission.

One of the best things about ars technica is the incredible expertise lurking in the forums. I suspect mperrin is Dr. Marshall Perrin, "member of the Telescopes group at STScI, working on issues of wavefront control, optical modeling, and high contrast imaging in support of the James Webb Space Telescope." (In layman terms, one of the world experts on infra-red optics.)

Thanks for the post.

Ha, outed. :-) And I wouldn't go quite that far... Let's just say I'm a junior faculty member aspiring to someday achieve world expert status, and lucky enough to work right now with the men and women who already have. I've only been part of the JWST team for a couple years - the vast, vast majority of the credit belongs to others.

And yeah, I totally agree that the community here is one of the best parts. I love reading all the biotech and particle physics and semiconductor technology discussions here, stuff that's way outside my area of expertise, and am glad to chip in with my $0.02 when relevant to space astronomy. (Hmm, or maybe that should be $0.02x10^9, given typical space mission costs?)